Rh immune globulin (RhIg) prophylaxis is given at 28 weeks and postpartum if the newborn is Rh-positive. Which option reflects this timing?

• A. Postpartum only
• B. 20 weeks
• C. 28 weeks
• D. 32 weeks

Answer: (C)

Rh immune globulin prophylaxis prevents the mother’s immune system from forming anti-D antibodies in response to fetal Rh-positive red cells. The prenatal dose is given around 28 weeks gestation to neutralize any fetal Rh-positive cells that may enter maternal circulation during late pregnancy. A second dose is given postpartum within about 72 hours after birth if the newborn is Rh-positive, to prevent sensitization from exposure during delivery. Among the options, the timing that matches this prenatal protection is 28 weeks. The postpartum-only option misses the prenatal safeguard, and the other weeks are not the standard prenatal timing.